Process of making fertilizer.



JOSEPH ELLSWORTH ZILK, or PITTSBURGH, PnNNstrLvANIA, ASSIGNOR ro .onoommss.

No Drawing. Original application filedNovember 11, 1916, Serial No. 130,835. Divided and this application filed February 10, 1917. Serial No. 147,887.

are;

-FIEJBTIIILIZ EB. MANUFACTURING COMPANY, OF PITTSBURGH, PENNSYLVANIA, A

CORPORATION Oil? DELAWARE.

PROCESS OF MAKING FERTILIZER.

To all whom it may. concern:

Be .it known that I, JosEr'H E. ZILK, a

'citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Processes of Making Fertilizer, of which'the following of processes in whichthe phosphate rockis is a specification. V a

The present invention relates to the production of phosphaticfertilizers from phosphate rock, by animprovement in that class heated with other materials.

The process of the present invention comprises heating phosphate rock with lime- 1 stone in the presence of coke and a sultable flux, the entire material being heated preferably: being introduced into theupper end of a rotary kiln, and being heated therein until ,a particular physical condition is-produced v in the mass, by virtue of which the product is readily ground or pulverized, and in which a considerable proportion of the phosphoric acid is in a condition in;which it is available-as plant food.

,The present caseis a divisiorrof my prior 1 application 130,835, filed November 11, 1916.

application I take 2000 pounds of crude phosphate,

\ In carryin out the vprocess of the present may proceed as follows:

rock, containing about of. phosphoric 'anhydrid (P 0 pulverize' the same in a v suitable mill, so that about 80% of itwill pass a screen having 100 meshes per linear inch. To this I then add'about 200 to 300 pounds (preferably about 300) of ground limestone,.ab'out 200 to 300 of ground coke and about 400 pounds of niter cake.

The material is then thoroughly mixed,

and preferably moistened with water sufliciently to form a paste. This is then introduced into a kiln which may be an ordinary rotary cement kiln and heated therein to a temperature of from 1300 to 1700 F. The material should be maintained in the kiln at this high temperature for a considerable 4 time, say? 5 to 90 minutes. Care should be taken, however, not. to ver' much exceed this temperature, since at the gher tempera- Spe'cification of Letters Patent.

' Patented Now. so, 1917.

tures, a hard clinker would be produced,

which would be difficult to grind, and which would also not contain as hlgh a percentage of available phos horic acid as that produced by the'pre erred temperature above stated. The kiln may be heated with any kind of suitable fuel, for example coal dust,

gas or fuel oil. The heating is-efiected in the manner commonly employed in cement kilns, namely by introducing a blast of fuel left the zone of highest temperature in the kiln, thecoke ,dustitself burns and thereby aids in the production 0 a light,.porous, readily crushed mass of-rounded-nodules,

in WhlCll there is a considerable proportion. of the phosphoric acid available.

The nodules should leave the furnace in the condition above stated, and care should be exer'c'ised not to overheat the mass, which would produce hard, completely clinkered nodules.

I am aware that various mixtures of phos-' phate rock and similar material have been heated to high temperatures, temperatures around 2,00cw 2,7009 F. having been previously suggested. Ihave found that the heating for a considerable time, at a temperature too low to produce a hard clinker, but high enough to produce a semi-clinkering of the mass, with the production of soft ature fora considerable time, enables me to produce products having the valuable quali ties above referred to. WhatIclaim is:"'

nodules, and the maintaining of this temper- 1. The process of making a fertilizer mamate mixture of phosphate rock, coke, limeture, under conditions capable of producing the combustion of said coke ,"to a temperature suificient to convert --the mass into readily crushed nodules, while avoiding, such high temperatures as would produce com-' terial which comprises producing an intistone andlniter cake, and heating the mixj lizer Which comprises heating only to incipient clinkering, an intimate mixture of Phosphate rock about 2000 lbs. Coke 200 to 300 lbs. Pulverized limestone 200 to 300 lbs. Niter cake 400 lbs.

and thereafter grinding the mass;

3. The process of making a fertilizer ma- 0 terial which comprises producing an intiemme mate mixture of phosphate rock, coke, limestone and a salt of an alkali metal, and heatcomplete clinkering of the mass.

In testimony whereof ll aflix my signature.

JOSEPH ELLSWURTH ZILK.

I such high temperatures, as would produce 

